(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code VariantConstructorArity)
  (message "enum constructor `Reading.Value` requires one string payload argument")
  (file "<fixture>")
  (span
    (bytes 74 89)
    (range 8 3 8 18)
  )
  (expected "1")
  (found "0")
)